<!DOCTYPE html>
<title>CSS Anchor Positioning: try-tactic under different writing modes</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#typedef-position-try-fallbacks-try-tactic">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
@position-try --pf {
left:10px;
top:20px;
}
#cb {
position: absolute;
width: 400px;
height: 400px;
border: 1px solid black;
}
#target {
position: absolute;
left: 99999px; /* force fallback */
width: 30px;
height: 40px;
background-color: skyblue;
}
</style>
<div id=cb>
<div id=target></div>
</div>
<script>
function test_try_tactic_wm(try_tactic, writing_mode, direction, expected_offsets) {
target.style.positionTryFallbacks = `--pf ${try_tactic}`;
target.style.writingMode = writing_mode;
target.style.direction = direction;
test(() => {
assert_equals(target.offsetLeft, expected_offsets.left, 'offsetLeft');
assert_equals(target.offsetTop, expected_offsets.top, 'offsetTop');
assert_equals(target.offsetWidth, expected_offsets.width, 'offsetWidth');
assert_equals(target.offsetHeight, expected_offsets.height, 'offsetHeight');
}, `${try_tactic} ${writing_mode} ${direction}`);
}
test_try_tactic_wm('', 'horizontal-tb', 'ltr', {left:10, top:20, width:30, height:40});
// Effectively flips left:10px to right:10px:
test_try_tactic_wm('flip-inline', 'horizontal-tb', 'ltr', {left:360, top:20, width:30, height:40});
// Effectively flips top:20px to bottom:20px:
test_try_tactic_wm('flip-inline', 'vertical-lr', 'ltr', {left:10, top:340, width:30, height:40});
// Mirror across the [left,top]=>[bottom,right] diagonal:
test_try_tactic_wm('flip-start', 'horizontal-tb', 'ltr', {left:20, top:10, width:40, height:30});
// Mirror across the [right,top]=>[bottom,left] diagonal:
test_try_tactic_wm('flip-start', 'horizontal-tb', 'rtl', {left:340, top:360, width:40, height:30});
</script>
Codebase Browser
chromium